GWD-27-22马上就要考了，求救！

Q22:

Whales originated in the freshwater lakes and rivers of ancient Asia about sixty million years ago.  Not until about ten million years later did species of whales develop specialized kidneys enabling them to drink salt water.  Although fossil evidence shows that some early whale species that lacked such kidneys sometimes swam in the Earth’s saltwater oceans, these species must have had to return frequently to freshwater rivers to drink.

Which of the following is most strongly supported by the information given?

1. Fossils of whale species dating from between sixty million and fifty million years ago will not be found on continents that were at the time separated from ancient Asia by wide expanses of ocean.

2. Among whale fossils that date from later than about fifty million years ago, none are fossils of whale species that drank only fresh water.

3. Fossils of whale species that drank fresh water will not be found in close proximity to fossils of whale species that drank salt water.

4. The earliest whales that drank salt water differed from fresh-water-drinking whales only in their possession of specialized kidneys.

5. Between sixty million and fifty million years ago, the freshwater lakes and rivers in which whales originated were gradually invaded by salt water.

   Answer: A

原文：whale60m年前在asia淡水中，50m年前有了特殊的肾使得他们能够在在海里生存。

结论：尽管一些化石证明没有这种肾的w也能在海里玩耍，但是他们还是必须要经常去淡水区域。

A：60-50年前这段时间（还没有进化出特殊的肾脏），在当时是广阔海域现在是大陆的地方没有发现w的化石。 

这证明了w不能在广阔的海域生存，因为他们需要经常性的回到淡水区域

谢谢楼上的解答！

解释得太好了

thanks

翻译需要小小的改动一下:

A:60-50年前这段时间（还没有进化出特殊的肾脏），在当时被广阔海域从古亚洲分离开的大陆上没有发现W的化石。而不是说当时是海域现在变成了大陆。

其他的解释都很同意。

可这样怎么就推不出来了啊?在当时的大陆上没有发现化石 跟W在当时的海洋中不能长时间生存有什么关系啊  我读不懂了~~~求助~~~

淡水在大陆上,不可能在大海里

我选了E,根据结论

Although fossil evidence shows that some early whale species that lacked such kidneys sometimes swam in the Earth’s saltwater oceans, these species must have had to return frequently to freshwater rivers to drink.如果A正确,那么如何证明结论的前半部分? 必须回到淡水来喝水不等于不能在盐水中生存,也许可以生存,只是经常要到某地方喝水.或许只要喝上一口,就能象骆驼一样在沙漠生存好几个月.

看E, the freshwater lakes and rivers in which whales originated were gradually invaded by salt water.这样白鲸就能自如地从盐水return frequently to freshwater rivers to drink.也更好地支持了 about ten million years later did species of whales develop specialized kidneys enabling them to drink salt water. 因为,器官的进化确实是演化gradually